Effects of interactive metronome therapy on cognitive functioning after blast-related brain injury: A randomized controlled pilot trial.

Abstract

We report preliminary findings on the efficacy of interactive metronome (IM) therapy for the remediation of cognitive difficulties in soldiers with persisting cognitive complaints following blast-related mild-to-moderate traumatic brain injury (TBI). Forty-six of a planned sample of 50 active duty soldiers with persistent cognitive complaints following a documented history of blast-related TBI of mild-to-moderate severity were randomly assigned to receive either standard rehabilitation care (SRC) or SRC plus a 15-session standardized course of IM therapy. Primary outcome measures were Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Index Scores. Secondary outcome measures included selected subtests from the Delis-Kaplan Executive Functioning System (Trail Making Test and Color-Word Interference) and the Wechsler Adult Intelligence Scale-Fourth Edition (Symbol Search, Digit-Symbol Coding, Digit Span, and Letter-Number Sequencing) as well as the Integrated Visual and Auditory Continuous Performance Test. Significant group differences (SRC vs. IM) were observed for RBANS Attention (p = .044), Immediate Memory (p = .019), and Delayed Memory (p = .031) indices in unadjusted analyses, with the IM group showing significantly greater improvement at Time 2 than the SRC group, with effect sizes in the medium-to-large range in the adjusted analyses for each outcome (Cohen's d = 0.511, 0.768, and 0.527, respectively). Though not all were statistically significant, effects in 21 of 26 cognitive outcome measures were consistently in favor of the IM treatment group (binomial probability = .00098). The addition of IM therapy to SRC appears to have a positive effect on neuropsychological outcomes for soldiers who have sustained mild-to-moderate TBI and have persistent cognitive complaints after the period for expected recovery has passed.